It's not often that a person gets to investigate her own murder. But that's exactly the opportunity afforded to 18-year-old Ari Emory, heroine of C.J. Cherryh's newest novel, Regenesis (DAW, $25.95).

Cloned from her illustrious predecessor, a state-certified, genius-level mover and shaker, Ari inhabits the science station of Reseune on the planet Cyteen. (That name sound familiar? If so, that's because Cherryh's Cyteen won the Hugo for Best Novel in 1989.) With the help of her mentor Yanni and her bodyguards Florian and Catlin, Ari must use her native genetic potential to relearn all her old skills and knowledge base, allowing her to navigate among the plots and conspiracies that surround her.

When a scheme to terraform the planet Eversnow with newfangled "nanistics" results in the murder of one Dr. Patil, a new urgency attaches to Ari's education. Meanwhile, three enigmatic clones slowly mature in their tanks ....

This new tale is part of Cherryh's vast Alliance-Union saga, 27 novels to date, along with several pending works. The installments emerge at steady intervals, so getting a new one is no surprise—generally speaking. But this one is different, since it's a direct sequel to Cyteen, the story of Ari Emory Mark I, which appeared way back in 1988. As such, it joins a select company: long-delayed and much-anticipated successors to famous works.

Cherryh gets both new and old readers quickly up to speed with a concise infodump about the universe of 2424, where contending factions strive for power, prestige and profits. Her depiction of her protagonists is sharp and lively, and the reader gets the sense of massed, cumulative history and consequence, just as in, for instance, Poul Anderson's Psychotechnic League Series.

But as with all Cherryh's novels of late, forward movement of the story is slow and halting. I begin to suspect that Cherryh's fictional template is not genre SF but a much older example of storytelling: Lady Murasaki's The Tale of Genji (1021), whose 1200-plus pages focus on daily routines and psychological development among more than 400 characters. As the Wikipedia entry for Genji notes: "The work does not make use of a plot; instead, much as in real life, events just happen and characters evolve simply by growing older."

Cherryh's novel does not go to quite that extreme. But nearly 600 pages covering April to September in the life of a teen, however exceptional, is pushing the envelope.